Effect of increased feeding of dietary α‐linolenic acid by grazing on formation of the cis9,trans11–18:2 isoform of conjugated linoleic acid in bovine milk

Feeding systems such as grazing affect the fatty acid profile of bovine milk fat. In addition, milk fat is formed as the product of fatty acid metabolism in cow bodies before being secreted into milk. However, how grazing influences milk fatty acid profile through the metabolism has not been completely characterized. When fatty acid concentrations in Holstein milk were compared between grazing and non‐grazing periods, α‐linolenic acid was significantly higher in the grazing period than in the non‐grazing period. This could be explained with an increase in α‐linolenic acid feeding with grazing. α‐linolenic acid had a linear positive correlation with conjugated linoleic acid (9c,11t‐18:2) (CLA) and vaccenic acid (VA) during the grazing period, whereas CLA had higher correlation with linoleic acid rather than with α‐linolenic acid during the non‐grazing period. These data indicate that the high content of dietary α‐linolenic acid affects CLA and VA formation in milk of grazing periods via α‐linolenic acid metabolism into VA.     

Predicting chronosequential changes in carbon stocks of pachymorph bamboo communities in slash-and-burn agricultural fallow,northern Lao People’s Democratic Republic

In northern Lao People’s Democratic Republic, rising human population has drastically reduced the fallow period of slash-and-burn agriculture which has led to a considerable decrease in the carbon stock in these communities. We estimated chronosequential changes in the communities' carbon stocks, and established the relationship between the fallow period and fallow-period-average carbon stocks in three carbon pools of bamboo-dominated communities in hilly areas of the Luang Prabang Province, northern Lao People’s Democratic Republic. Based on measurements by destructive sampling, we devised a model and root-to-shoot ratios for estimating bamboo biomass. In six secondary plant communities established after slash-and-burn cropping, we estimated community biomass using the above model and others, and measured deadwood and litter stocks. The communities’ biomass and deadwood significantly increased with time after the last cropping and the former reached about 100 Mg ha⁻¹ after 15 years, whereas litter stocks did not show significant trends over time. Extending the fallow period from 2 to 5 years would increase fallow-period-average carbon stock from 14.2 to 25.1 Mg C ha⁻¹. The overstory height was significantly correlated with biomass, deadwood, and litter carbon stocks of these communities. Based on our findings, changes in a community’s carbon stocks can be estimated using the changes in overstory height, which should be taken into account in future studies to reduce uncertainty in estimating carbon stocks in tropical ecosystems.     

Effect of microwave decomposition on inductively coupled plasma spectrometry analysis of minerals in oysters

Fisheries Science - Oysters, which can be cultivated in oceans, are rich in nutrients. Recently, our group has reported the rapid analysis of multiple minerals in Crassostrea gigas oysters by...     

Blood pressure characteristics of female spontaneously diabetic Torii-Lepr(fa) rats

Blood pressure in female SDT-fa/fa rats was periodically investigated at ages 8, 16, and 24 weeks. Furthermore, an insulin therapy was performed for 5 weeks in the female rats at age 11 weeks, and the change of blood pressure was examined. In addition to obesity, hyperglycemia, hyperinsulinemia, and hyperlipidemia, hyperleptinemia and increased urinary angiotensinogen level were observed during the experimental period. Blood pressure was elevated at ages 8 and 16 weeks, but that at 24 weeks was comparable to that in Sprague-Dawley (SD) rats. Heart rate was decreased from age 8 to 24 weeks. Insulin therapy induced good glycemic control and improvement of hyperlipidemia, but the blood pressure was not reduced. Blood pressure in female SDT-fa/fa rats was elevated temporarily. The blood pressure was not decreased by insulin treatment. SDT-fa/fa rat is a useful model to investigate the relation between diabetes mellitus and hypertension.     

Physiological changes induced by salt intake in female Spontaneously Diabetic Torii‐Leprfa (SDT fatty) rat,a novel obese type 2 diabetic model

Salt plays an important role in the control of blood pressure in obesity and diabetes mellitus. In this study, we investigated physiological changes such as blood pressure and renal function in salt‐loaded female Spontaneously Diabetic Torii‐Lepr^fa (SDT fatty) rats. SDT fatty rats were given 1% NaCl in drinking water for 14 weeks, from 4 to 18 weeks of age. Significant salt‐sensitive hypertension was observed in the salt‐loaded SDT fatty rats. Moreover, the salt‐loaded rats showed a decrease of creatinine clearance and deterioration on pathological renal findings, including glomerulosclerosis and tubular and interstitial lesions. Female SDT fatty rat is a useful model for investigating the mechanisms of high salt sensitivity in obesity and diabetes mellitus.